SQLite

Check-in [f56c9884be]
Login

Many hyperlinks are disabled.
Use anonymous login to enable hyperlinks.

Overview
Comment:Go back to allocating each page and its header with a single memory allocation. This undoes the change of (4409). (CVS 4495)
Downloads: Tarball | ZIP archive
Timelines: family | ancestors | descendants | both | trunk
Files: files | file ages | folders
SHA1: f56c9884be796dee3f267aca6021eb1846d8527c
User & Date: drh 2007-10-20 13:17:55.000
Context
2007-10-20
15:41
Simplify the mem3.c memory allocator. Have it call sqlite3_release_memory() automatically, without having to specify the soft heap limit. (CVS 4496) (check-in: ca51b2f540 user: drh tags: trunk)
13:17
Go back to allocating each page and its header with a single memory allocation. This undoes the change of (4409). (CVS 4495) (check-in: f56c9884be user: drh tags: trunk)
12:34
Fix a mutex leak in the new malloc-free memory allocator. (CVS 4494) (check-in: 30f014d3d0 user: drh tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/pager.c.
︙︙
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.392 2007/10/03 15:22:26 danielk1977 Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include <assert.h>
#include <string.h>

/*








|








14
15
16
17
18
19
20
21
22
23
24
25
26
27
28

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.393 2007/10/20 13:17:55 drh Exp $
*/
#ifndef SQLITE_OMIT_DISKIO
#include "sqliteInt.h"
#include <assert.h>
#include <string.h>

/*
︙︙
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237

  PgHdr *pPg, *pNext;
  if( pPager->errCode ) return;
  for(pPg=pPager->pAll; pPg; pPg=pNext){
    IOTRACE(("PGFREE %p %d\n", pPager, pPg->pgno));
    PAGER_INCR(sqlite3_pager_pgfree_count);
    pNext = pPg->pNextAll;
    lruListRemove(pPg);
    sqlite3_free(pPg->pData);
    sqlite3_free(pPg);
  }
  assert(pPager->lru.pFirst==0);
  assert(pPager->lru.pFirstSynced==0);
  assert(pPager->lru.pLast==0);
  pPager->pStmt = 0;
  pPager->pAll = 0;








<








1223
1224
1225
1226
1227
1228
1229

1230
1231
1232
1233
1234
1235
1236

  PgHdr *pPg, *pNext;
  if( pPager->errCode ) return;
  for(pPg=pPager->pAll; pPg; pPg=pNext){
    IOTRACE(("PGFREE %p %d\n", pPager, pPg->pgno));
    PAGER_INCR(sqlite3_pager_pgfree_count);
    pNext = pPg->pNextAll;
    lruListRemove(pPg);

    sqlite3_free(pPg);
  }
  assert(pPager->lru.pFirst==0);
  assert(pPager->lru.pFirstSynced==0);
  assert(pPager->lru.pLast==0);
  pPager->pStmt = 0;
  pPager->pAll = 0;
︙︙
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543

      ppPg = &pPg->pNextAll;
    }else{
      *ppPg = pPg->pNextAll;
      IOTRACE(("PGFREE %p %d\n", pPager, pPg->pgno));
      PAGER_INCR(sqlite3_pager_pgfree_count);
      unlinkPage(pPg);
      makeClean(pPg);
      sqlite3_free(pPg->pData);
      sqlite3_free(pPg);
      pPager->nPage--;
    }
  }
}

/*








<








2528
2529
2530
2531
2532
2533
2534

2535
2536
2537
2538
2539
2540
2541

      ppPg = &pPg->pNextAll;
    }else{
      *ppPg = pPg->pNextAll;
      IOTRACE(("PGFREE %p %d\n", pPager, pPg->pgno));
      PAGER_INCR(sqlite3_pager_pgfree_count);
      unlinkPage(pPg);
      makeClean(pPg);

      sqlite3_free(pPg);
      pPager->nPage--;
    }
  }
}

/*
︙︙
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207

      nReleased += (
          sizeof(*pPg) + pPager->pageSize
          + sizeof(u32) + pPager->nExtra
          + MEMDB*sizeof(PgHistory) 
      );
      IOTRACE(("PGFREE %p %d *\n", pPager, pPg->pgno));
      PAGER_INCR(sqlite3_pager_pgfree_count);
      sqlite3_free(pPg->pData);
      sqlite3_free(pPg);
      pPager->nPage--;
    }else{
      /* An error occured whilst writing to the database file or 
      ** journal in pager_recycle(). The error is not returned to the 
      ** caller of this function. Instead, set the Pager.errCode variable.
      ** The error will be returned to the user (or users, in the case 








<








3191
3192
3193
3194
3195
3196
3197

3198
3199
3200
3201
3202
3203
3204

      nReleased += (
          sizeof(*pPg) + pPager->pageSize
          + sizeof(u32) + pPager->nExtra
          + MEMDB*sizeof(PgHistory) 
      );
      IOTRACE(("PGFREE %p %d *\n", pPager, pPg->pgno));
      PAGER_INCR(sqlite3_pager_pgfree_count);

      sqlite3_free(pPg);
      pPager->nPage--;
    }else{
      /* An error occured whilst writing to the database file or 
      ** journal in pager_recycle(). The error is not returned to the 
      ** caller of this function. Instead, set the Pager.errCode variable.
      ** The error will be returned to the user (or users, in the case
︙︙
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506

**     (4)  Either there is an available PgHdr that does not need
**          to be synced to disk or else disk syncing is currently
**          allowed.
*/
static int pagerAllocatePage(Pager *pPager, PgHdr **ppPg){
  int rc = SQLITE_OK;
  PgHdr *pPg;
  void *pData;

  /* Create a new PgHdr if any of the four conditions defined 
  ** above are met: */
  if( pPager->nPage<pPager->mxPage
   || pPager->lru.pFirst==0 
   || MEMDB
   || (pPager->lru.pFirstSynced==0 && pPager->doNotSync)
  ){
    if( pPager->nPage>=pPager->nHash ){
      pager_resize_hash_table(pPager,
         pPager->nHash<256 ? 256 : pPager->nHash*2);
      if( pPager->nHash==0 ){
        rc = SQLITE_NOMEM;
        goto pager_allocate_out;
      }
    }
    pagerLeave(pPager);
    pPg = sqlite3_malloc( sizeof(*pPg) + sizeof(u32) + pPager->nExtra
                            + MEMDB*sizeof(PgHistory) );
    if( pPg ){
      pData = sqlite3_malloc( pPager->pageSize );
      if( pData==0 ){
        sqlite3_free(pPg);
        pPg = 0;
      }
    }
    pagerEnter(pPager);
    if( pPg==0 ){
      rc = SQLITE_NOMEM;
      goto pager_allocate_out;
    }
    memset(pPg, 0, sizeof(*pPg));
    if( MEMDB ){
      memset(PGHDR_TO_HIST(pPg, pPager), 0, sizeof(PgHistory));
    }
    pPg->pData = pData;
    pPg->pPager = pPager;
    pPg->pNextAll = pPager->pAll;
    pPager->pAll = pPg;
    pPager->nPage++;
  }else{
    /* Recycle an existing page with a zero ref-count. */
    rc = pager_recycle(pPager, &pPg);








|

















|
|
<
|
<
<
<
<
<





|
<
<
<
|








3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479

3480





3481
3482
3483
3484
3485
3486



3487
3488
3489
3490
3491
3492
3493
3494

**     (4)  Either there is an available PgHdr that does not need
**          to be synced to disk or else disk syncing is currently
**          allowed.
*/
static int pagerAllocatePage(Pager *pPager, PgHdr **ppPg){
  int rc = SQLITE_OK;
  PgHdr *pPg;
  int nByteHdr;

  /* Create a new PgHdr if any of the four conditions defined 
  ** above are met: */
  if( pPager->nPage<pPager->mxPage
   || pPager->lru.pFirst==0 
   || MEMDB
   || (pPager->lru.pFirstSynced==0 && pPager->doNotSync)
  ){
    if( pPager->nPage>=pPager->nHash ){
      pager_resize_hash_table(pPager,
         pPager->nHash<256 ? 256 : pPager->nHash*2);
      if( pPager->nHash==0 ){
        rc = SQLITE_NOMEM;
        goto pager_allocate_out;
      }
    }
    pagerLeave(pPager);
    nByteHdr = sizeof(*pPg) + sizeof(u32) + pPager->nExtra
              + MEMDB*sizeof(PgHistory);

    pPg = sqlite3_malloc( nByteHdr + pPager->pageSize );





    pagerEnter(pPager);
    if( pPg==0 ){
      rc = SQLITE_NOMEM;
      goto pager_allocate_out;
    }
    memset(pPg, 0, nByteHdr);



    pPg->pData = (void*)(nByteHdr + (char*)pPg);
    pPg->pPager = pPager;
    pPg->pNextAll = pPager->pAll;
    pPager->pAll = pPg;
    pPager->nPage++;
  }else{
    /* Recycle an existing page with a zero ref-count. */
    rc = pager_recycle(pPager, &pPg);
︙︙